[PATCH v9 07/12] drm/i915/psr: Modify intel_dp_get_su_granularity to support panel replay

[Manna, Animesh]

> -----Original Message-----
> From: Hogander, Jouni <jouni.hogander at intel.com>
> Sent: Friday, May 3, 2024 12:04 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Manna, Animesh <animesh.manna at intel.com>; Hogander, Jouni
> <jouni.hogander at intel.com>
> Subject: [PATCH v9 07/12] drm/i915/psr: Modify intel_dp_get_su_granularity
> to support panel replay
> 
> Currently intel_dp_get_su_granularity doesn't support panel replay.
> This fix modifies it to support panel replay as well.
> 
> v4:
>   - use drm_dp_dpcd_readb instead of drm_dp_dpcd_read
>   - ensure return value is 0 if drm_dp_dpcd_readb fails
> v3: use correct offset for DP_PANEL_PANEL_REPLAY_CAPABILITY
> v2: rely on PSR definitions on common bits
> 
> Signed-off-by: Jouni Högander <jouni.hogander at intel.com>

Reviewed-by: Animesh Manna <animesh.manna at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_psr.c | 62 +++++++++++++++++++++---
>  1 file changed, 55 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index b94f8e33ed1f..5e5ef432b931 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -466,6 +466,40 @@ static u8 intel_dp_get_sink_sync_latency(struct
> intel_dp *intel_dp)
>  	return val;
>  }
> 
> +static u8 intel_dp_get_su_capability(struct intel_dp *intel_dp) {
> +	u8 su_capability = 0;
> +
> +	if (intel_dp->psr.sink_panel_replay_su_support)
> +		drm_dp_dpcd_readb(&intel_dp->aux,
> +				  DP_PANEL_PANEL_REPLAY_CAPABILITY,
> +				  &su_capability);
> +	else
> +		su_capability = intel_dp->psr_dpcd[1];
> +
> +	return su_capability;
> +}
> +
> +static unsigned int
> +intel_dp_get_su_x_granularity_offset(struct intel_dp *intel_dp) {
> +	return intel_dp->psr.sink_panel_replay_su_support ?
> +		DP_PANEL_PANEL_REPLAY_X_GRANULARITY :
> +		DP_PSR2_SU_X_GRANULARITY;
> +}
> +
> +static unsigned int
> +intel_dp_get_su_y_granularity_offset(struct intel_dp *intel_dp) {
> +	return intel_dp->psr.sink_panel_replay_su_support ?
> +		DP_PANEL_PANEL_REPLAY_Y_GRANULARITY :
> +		DP_PSR2_SU_Y_GRANULARITY;
> +}
> +
> +/*
> + * Note: Bits related to granularity are same in panel replay and psr
> + * registers. Rely on PSR definitions on these "common" bits.
> + */
>  static void intel_dp_get_su_granularity(struct intel_dp *intel_dp)  {
>  	struct drm_i915_private *i915 = dp_to_i915(intel_dp); @@ -473,18
> +507,29 @@ static void intel_dp_get_su_granularity(struct intel_dp
> *intel_dp)
>  	u16 w;
>  	u8 y;
> 
> -	/* If sink don't have specific granularity requirements set legacy ones
> */
> -	if (!(intel_dp->psr_dpcd[1] &
> DP_PSR2_SU_GRANULARITY_REQUIRED)) {
> +	/*
> +	 * TODO: Do we need to take into account panel supporting both PSR
> and
> +	 * Panel replay?
> +	 */
> +
> +	/*
> +	 * If sink don't have specific granularity requirements set legacy
> +	 * ones.
> +	 */
> +	if (!(intel_dp_get_su_capability(intel_dp) &
> +	      DP_PSR2_SU_GRANULARITY_REQUIRED)) {
>  		/* As PSR2 HW sends full lines, we do not care about x
> granularity */
>  		w = 4;
>  		y = 4;
>  		goto exit;
>  	}
> 
> -	r = drm_dp_dpcd_read(&intel_dp->aux,
> DP_PSR2_SU_X_GRANULARITY, &w, 2);
> +	r = drm_dp_dpcd_read(&intel_dp->aux,
> +			     intel_dp_get_su_x_granularity_offset(intel_dp),
> +			     &w, 2);
>  	if (r != 2)
>  		drm_dbg_kms(&i915->drm,
> -			    "Unable to read
> DP_PSR2_SU_X_GRANULARITY\n");
> +			    "Unable to read selective update x granularity\n");
>  	/*
>  	 * Spec says that if the value read is 0 the default granularity should
>  	 * be used instead.
> @@ -492,10 +537,12 @@ static void intel_dp_get_su_granularity(struct
> intel_dp *intel_dp)
>  	if (r != 2 || w == 0)
>  		w = 4;
> 
> -	r = drm_dp_dpcd_read(&intel_dp->aux,
> DP_PSR2_SU_Y_GRANULARITY, &y, 1);
> +	r = drm_dp_dpcd_read(&intel_dp->aux,
> +			     intel_dp_get_su_y_granularity_offset(intel_dp),
> +			     &y, 1);
>  	if (r != 1) {
>  		drm_dbg_kms(&i915->drm,
> -			    "Unable to read
> DP_PSR2_SU_Y_GRANULARITY\n");
> +			    "Unable to read selective update y granularity\n");
>  		y = 4;
>  	}
>  	if (y == 0)
> @@ -588,7 +635,8 @@ void intel_psr_init_dpcd(struct intel_dp *intel_dp)
>  	if (intel_dp->psr_dpcd[0])
>  		_psr_init_dpcd(intel_dp);
> 
> -	if (intel_dp->psr.sink_psr2_support)
> +	if (intel_dp->psr.sink_psr2_support ||
> +	    intel_dp->psr.sink_panel_replay_su_support)
>  		intel_dp_get_su_granularity(intel_dp);
>  }
> 
> --
> 2.34.1